The NHS was long the Conservative party's achilles heel. David Cameron's greatest political achievement as leader of the opposition was to neutralise health as an issue. The greatest mistake of his time as prime minister has been to put it back at the centre of political debate.

Many Conservatives think that the NHS needs fundamental reform, but for far-reaching reform to succeed certain preonditions must be met. The public needs to have been persuaded that substantial change is necessary. The government cannot be distracted by other consuming projects; its best brains must be focused and single-minded in ensuring the policy's success. The Whitehall machine needs to be prepared and co-operative. The health secretary needs to enjoy significant goodwill amongst NHS staff and possess exceptional communication skills.

Few – perhaps none – of those preconditions exist.

Earlier this week David Cameron and Nick Clegg decided again that they would plough on with the health and social care bill. Clegg was particularly reluctant. Cameron was resigned to doing so. Neither were enthusiastic.

In the wake of Rachel Sylvester's seismic article in Tuesday's Times, it is now clear that concern is high at the top table of the coalition. Sylvester revealed the extent of concern inside Downing Street. Speaking to ConservativeHome, three Tory cabinet ministers have now also rung the alarm bell. One was insistent the bill must be dropped. Another said Andrew Lansley must be replaced. Another likened the NHS reforms to the poll tax. The consensus is that the prime minister needs an external shock to wake him to the scale of the problem.

The few people who remain in the stay-the-course camp point to the latest YouGov polling. They say that the NHS isn't at the top of voters' concerns. Only 25% of voters think it's one of the top three issues facing the country. But the state of public opinion today isn't the issue. The issue is public opinion next winter and in the winter of 2013/14 and beyond.

The NHS has always gobbled up resources and creaked. The creaking was severe when spending was increasing by 3% or 4% in real terms every year. What do you think it's going to be like when spending is increasing by 0.1% year after year in this longest ever period of UK-wide austerity? The creaking could have been blamed on the empty Treasury and Labour's over-borrowing. Not now. It will now be unfairly blamed on the bill, and a bill that is not only mangled and bureaucratic, but also unnecessary.

Most observers think that meeting "the Nicholson challenge" – £20bn of essential efficiency savings – was always going to be nightmarishly difficult, but that it didn't require new legislation. Nearly all of the necessary efficiencies could have been delivered with existing powers. That has certainly been the consistent argument of Stephen Dorrell MP, the influential chairman of the commons health select committee.

The NHS bill emerged during the early days of the coalition. Cameron and Clegg seemed to think the normal laws of politics had been suspended in the weeks following their rose garden romance. Desperate to prove that their alliance was not a lowest common denominator arrangement, they over-reached and the Lansley bill was born. George Osborne might have been expected to veto such an over-reach. Osborne is the party's master strategist and co-architect of the opposition years' strategy to take the NHS off-the-table. Unfortunately and inevitably, he was focused on the small matter of being the new chancellor of the exchequer during the period in which the NHS bill was drawn up and signed off.

Soon, in a wider reshuffle, Andrew Lansley will have to move on. He will have to move on because he hasn't been able to communicate these reforms in a streetwise way, and he has been unnecessarily confrontational with NHS staff. It would be very wrong, however, for him to take the full blame. Cameron and Clegg both put their signatures on the reforms. Oliver Letwin went through the draft legislation with a fine-tooth comb, supposedly bomb-proofing them. And, then, after last year's pause, the whole cabinet consented to the compromises with the Lib Dem rebels and NHS professionals. Lansley is a man of integrity and intellectual seriousness. Unfortunately, however, the NHS has become a big negative for our party again and it's easier to move forward with a new frontman or a new frontwoman.

Cameron now has a very difficult choice between two very tricky paths.

Path one involves removing all contentious components of the bill. That might mean sitting down with Baroness (Shirley) Williams and other leading rebels. Perhaps, even, with shadow health secretary Andy Burnham. It means passing a bill which contains the genuinely new and exciting provisions on public health, but much else would have to be deleted and discarded. It would be humiliating to forge such a cross-party deal but the humiliation would subside over a few weeks.

Path two involves pressing on. It's the path that, despite his rhetoric, Ed Miliband prays the coalition will tread. Pressing on avoids the immediate political pain but leaves the chronic electoral problem in place. By "succeeding" in enacting a contentious bill every inevitable problem that arises in the NHS in the years ahead will be blamed on it. That's a heavy price to pay for a bill that is neither transformational nor necessary. Cameron must take path one or the already uphill struggle at the next election becomes mountainous.

ConservativeHome supports the government's radicalism on schools, welfare and the deficit. We'd like to see much more ambition on competitiveness and changing Britain's relationship with Europe. The NHS bill is not just a distraction from all of this, but potentially fatal to the Conservative party's electoral prospects. It must be stopped before it's too late.